package codetop.microsoft.T96;

/**
 * @Author: 18362
 * @Create: 2022-08-15 12:05:17 星期一
 */
class Solution {
    public int numTrees(int n) {
        int[] dp = new int[n+1];
        dp[0] = 1;
        dp[1] = 1;
        for (int i=2; i<=n; ++i) {
            for (int j=0; j<i; ++j) {
                dp[i] += (dp[j] * dp[i-j-1]);
            }
        }
        return dp[n];
    }
}